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First-trimester maternal plasma cell-free fetal DNA and preeclampsia.
Sifakis S, Zaravinos A, Maiz N, Spandidos DA, Nicolaides KH.
Am J Obstet Gynecol 2009;201:472.1-7. -
Prediction of pregnancy complications by first-trimester maternal serum PAPP-A and free beta-hCG and with second-trimester uterine artery Doppler.
Spencer K, Yu CK, Cowans NJ, Otigbah C, Nicolaides KH.
Prenat Diagn 2005;25:949-53.